Research On The Satellite Networking Mechanism For Quantum Key Distribution

With the rapid development of technology and the advent of quantum computer,the traditional encryption method based on complex mathematical computation is facing a huge threat.How to ensure the security of global network communication is an urgent problem.Quantum key distribution(QKD)can generate theoretical-secure key,which has unique advantages in ensuring communication security.Because of the limitation of fiber channel loss,the ground QKD network can not realize the sharing of key between two ends of the long distance.For long-distance or intercontinental users,satellite-ground QKD provides the most appealing solution,owing to the low transmission attenuation and negligible decoherence of quantum signals in space..Using quantum satellite as a trusted relay node to complete the remote QKD request,intercontinental and even global QKD can be realized.However,there is only one quantum satellite in free space at present.In order to provide secure communication with global coverage,it is necessary to deploy a quantum satellite network containing multiple quantum satellites.This raises the question:how to build a quantum satellite network so as to have better key-relay capability.In order to solve the above problems,this paper focuses on the problem of "how to build a quantum satellite network and how to use key resources",designs the networking architecture of quantum satellite network,and proposes the routing and key resource distribution strategy of quantum satellite network.This paper mainly studies from the following three aspects:Firstly,aiming at the problem of the network structure design of quantum satellite network,a centralized and distributed cooperative key distribution network architecture of quantum satellite network is proposed.The architecture is based on SDN technology.By deploying the master controller and sub domain controller,it can globally control the network connection and resources,so as to make the routing and key resource distribution strategy more intelligent and reasonable.Secondly,aiming at the problem of how to distribute the key resources of quantum satellite network,a single-path routing and key resource distribution(S-RKRA)method is proposed,and the key resource consumption model of quantum satellite network is established.Based on the various forms of Leo quantum satellite constellation,the effects of node,orbit number,link form and service number on the key relay performance of the algorithm are discussed.The simulation results show that the presence or absence of IOL in the quantum satellite network will cause a difference of up to 50%of the service success rate,even when the traffic is relatively large,it can also bring a difference of 20%.Thirdly,aiming at the efficient distribution of key resources in quantum satellite networks for QKD,a multi-path routing and key resource distribution algorithm based on quantum key resource surplus ratio(RR-M-RKRA)is proposed.In this scheme,the method of generating quantum key by multi-path and the concept of key resource surplus degree are proposed.The influence of the number of keys remaining in the key pool on the QKD performance of LEO quantum satellite constellation is considered.The simulation results show that the success rate of key relay service of RR-M-RKRA algorithm can be increased by 20%compared with S-RKRA algorithm.When R is 0.4,RR-M-RKRA algorithm has the best effect,and the performance can be improved by 18%.